KR100681493B1 - Antireflective Coating Composition with Excellent Stain Resistance - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition for forming a coating layer that is easily decontaminated and has an antireflection function. The present invention relates to a sol-gel reactant prepared from alkoxysilane, fluorine-based silane, catalyst, water, and an organic solvent, and a conductive polymer. It relates to a display antireflective coating composition comprising.

The coating composition of the present invention is useful as a display anti-reflective coating substrate because it can exhibit the anti-reflective property and the removal property against liquid contaminants such as fingerprints and dust removal by controlling the refractive index, surface energy and conductivity of the coating layer. Can be used.

Anti-reflective, Coating composition, Fluorine-based silane, Conductive polymer

Description

Antireflective Coating Composition with Excellent Stain Resistance

[Industrial use]

The present invention relates to a coating composition for easily decontamination and to form a coating layer having an antireflection function, and more particularly, to a coating composition comprising a fluorine-based silane having a low surface tension, a conductive polymer having an antistatic property, and a solvent. It is about.

 [Private Technology]

Displays such as CRTs for monitors, CRTs such as CPTs for TVs, TFT-LCD polarizers, PDP filters, RPTS filters, cell phones, liquid crystals, clocks, photographs, picture frames, etc. are being encountered in our lives. When the display is exposed to light such as natural light, the eyes may feel tired or cause headaches due to the reflected light, and the image produced inside the display may not be clearly formed in the eye, resulting in a decrease in contrast.

In order to solve this problem, there have been studies to develop a low reflection coating layer which reduces the reflectance by inducing extinction interference. In Japanese Patent Laid-Open No. 97-208898, Japanese Patent Laid-Open No. 96-122501, etc., a low reflection layer having a refractive index of 1.28-1.38 was prepared using a silicic acid compound and a metal fluoride of magnesium fluoride (MgF ₂ ). Patent No. 776925 discloses the preparation of a coating liquid having a low reflection function and a fouling resistance function according to a decrease in surface energy by using a compound having a fluorine silane and a fluorine alkyl group.

However, the low reflection layer into which the metal fluoride or fluorine is introduced has a disadvantage that the charge easily adheres to the surface by friction or the like, and the dust adheres well, and the dust once adhered does not fall easily. In particular, since the low reflection layer is usually located at the outermost side of the display, it should be resistant to contamination sources such as fingerprints and dust. In this case, having resistance means that the surface energy is low and fingerprints are not easily attached, and the charge on the surface flows without being offset or stayed so that dust does not adhere to the electrostatic attraction.

Therefore, there have been reported methods for preventing the adhesion of dust and the like by not applying a static charge on the surface. Japanese Patent Application Laid-Open No. 94-65529 discloses tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), antimony-doped zinc oxide (Antimony- Conductive metal oxide fillers such as doped zinc oxide (AZO) are used, but when the conductive metal oxide is used, the refractive index is generally high and antireflection effects cannot be expected and the ability to remove liquid contaminants such as fingerprints is not realized.

In addition, Japanese Patent Application Laid-Open No. 2003-215306 attempts to improve the ability to remove solid contaminants such as dust and liquid contaminants such as fingerprints by introducing functional groups and fluorine compounds in which positive and negative charges coexist, but they are sensitive to seasonal environment. There is a disadvantage in that the removal to the liquid pollution source is lowered.

Therefore, there is an urgent need to develop a display anti-reflective coating composition capable of simultaneously controlling the refractive index, surface energy, and conductivity of the coating layer to exhibit anti-reflective properties, erosion of liquid contaminants such as fingerprints, and dust removal.

In order to solve the above problems, the present invention provides antireflection function due to low refractive index and at the same time easy to remove the contamination through low surface energy and antistatic, to form a coating layer that can be suitably applied to the front of the display To provide a display antireflective coating composition for that purpose.

In order to achieve the above object, the present invention is (a) 0.3 to 15 parts by weight of (i) alkoxysilane, (ii) 0.1 to 10 parts by weight of fluorine-based silane, (iii) 0.001 to 0.5 parts by weight of catalyst, (iv) water 0.01 To 10 parts by weight, and (v) a sol-gel reactant prepared from 20 to 99.5 parts by weight of an organic solvent, and (b) 0.02 to 50 parts by weight of a conductive polymer.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The inventors of the present invention are developing a coating composition that can be applied to the front surface of a display by providing anti-reflection function due to low refractive index and at the same time easy to remove contamination through low surface energy and antistatic property. Alkoxysilane for implementation, a coating composition comprising a conductive polymer to have an antistatic effect on the surface of the film in order to give a removal function of the solid contaminants such as fluorine-based silane and dust having a low refractive index and excellent ease of removal of liquid contaminants It was developed to complete the present invention.

The antireflective coating composition of the present invention comprises (a) 0.3 to 15 parts by weight of (i) alkoxysilane, (ii) 0.1 to 10 parts by weight of fluorine silane, (iii) 0.001 to 0.5 parts by weight of catalyst, and (iv) 0.01 to water. 10 parts by weight, and (v) a sol-gel reactant prepared from 20 to 99.5 parts by weight of an organic solvent, and (b) 0.02 to 50 parts by weight of a conductive polymer.

The alkoxysilane is a component for providing a film strength of the level that can be used for the outermost display, tetramethoxysilane, tetraethoxysilane, tetraethoxysilane, methyltrimethoxysilane, trimethylsilicon, Ethoxysilane, glycidoxypropyl trimethoxysilane, glycidoxypropyl triethoxysilane, and the like can be used.

When the content of the alkoxysilane used in the preparation of the sol-gel reactant is less than 0.3 parts by weight, it is difficult to maintain the hardness of the coating film for display, and when it exceeds 15 parts by weight, the curing degree of the coating film is high, which may cause curling. The adhesion between the substrate and the coating film may be reduced.

Fluorine-based silane used in the preparation of the sol-gel reactant is a component that lowers the refractive index and facilitates the removal of liquid contaminants, tridecafluorooctyltriethoxysilane (trade name: DYNASYLAN F8261, Degussa-Huls), hepta Decafluorodecyltrimethoxysilane (trade name: TSL8233, Toshiba silicon; KBM-7803, Shinetsu), heptadecafluorodecyltriisopropoxysilane (trade name: XC95-A9715, Toshiba Silicone) have.

When the content of the fluorine-based silane used in the preparation of the sol-gel reactant is less than 0.1 part by weight, the refractive index control and fouling resistance of the coating film are insignificant, and when the content is greater than 10 parts by weight, the strength of the film may be reduced. .

In addition, the fluorine-based silane is preferably used in an amount of 10 to 50% by weight compared to the total silane of the alkoxysilane and the fluorine-based silane. When using less than 10% by weight, the effect of controlling the refractive index and removing the liquid pollutant is insignificant, 50 In the case where it is used in an amount exceeding% by weight, it is difficult to control the appropriate molecular weight by the sol-gel reaction and the strength of the film may be lowered.

In addition, when the content of the organic solvent is less than 20 parts by weight or more than 99.5 parts by weight, the coating property may be reduced.

The organic solvent is preferably alcohols, cellosolves, ketones, or two or more mixed solvents selected from these. Preferred examples of the alcohol solvent include at least one selected from the group consisting of methanol, ethanol, propanol and butanol, and preferred examples of the cellosolve solvents include ethyl cellosolve, butyl cellosolve, hexyl cellosolve, and methyl cello. There is at least one selected from the group consisting of sorb and isopropoxy cellosolve, a preferred example of the ketone solvent is at least one selected from the group consisting of acetone, methyl ethyl ketone, diacetone alcohol and methyl isobutyl ketone have.

The fluorine-based silane and the conductive polymer included in the sol-gel reactant of the coating composition may not have good compatibility with each other and may cause phase separation in the coating composition. Accordingly, in order to suppress phase separation between the fluorine-based silane and the conductive polymer in the display antireflective coating composition, the organic solvent includes an alcohol solvent which is a low boiling point (about 100 ° C. or less) solvent, and has a medium boiling point (about 100 ° C. to 150 ° C.). It is preferable that it is a mixed solvent further containing 1 or more types chosen from the group which consists of a ketone solvent which is C) solvent, and a cellosolve solvent. The content of the middle boiling point solvent included in the mixed solvent is preferably 30% by weight or less, more preferably 1 to 20% by weight based on the total weight of the mixed solvent. When the content of the middle boiling point solvent of the mixed solvent exceeds 30% by weight, phase separation of the fluorine-based silane and the conductive polymer may occur and the drying time of the solution may not be dried.

The catalyst may be an acid such as nitric acid, hydrochloric acid, acetic acid, or a salt thereof, and a mixture of the acid and the salt may be used. The salts available may include hydrochlorides such as zirconium and indium, nitrates, sulfates, acetates, and the like. have. In this case, the catalyst is preferably used in 0.001 to 0.5 parts by weight, when using less than 0.001 parts by weight, there is a problem in controlling the sol-gel reaction time, when using more than 0.5 parts by weight of the acidity of the solution There is a problem of corrosion.

The water is a component necessary for the hydrolysis reaction and the condensation reaction, it is preferably used in 0.01 to 10% by weight. When using less than 0.01 parts by weight, there is a problem in controlling the sol-gel reaction time, and when used in excess of 10% by weight, there is a problem in coating property.

The conductive polymer is a component to have an antistatic effect on the surface of the film in order to give a function of removing solid contaminants such as dust, it is preferable to use a polythiophene-based resin such as polyethylene dioxythiophene resin. In particular, a doping agent such as glutamic acid, alkyl sulfonic acid, polystyrene sulfonic acid anion, styrene sulfonic acid and styrene sulfonic acid anion copolymer, or the like may be added to the polythiophene resin to improve conductivity. Presently commercialized and widely used conductive polymers include Bayerron P (Baytron P), PH, P HS, P HC, PET V2, etc. having a structure of polyethylenedioxythiophene-polystyrenesulfonate, and two or more kinds thereof. It can also be mixed and used.

When the content of the conductive polymer is less than 0.02 parts by weight, the ease of removal of solid contaminants such as dust may be reduced, and when used in excess of 50 parts by weight, the strength of the film may be reduced.

In order to prepare a display antireflective coating composition of the present invention, (a) 0.3 to 15 parts by weight of (i) alkoxysilane, (ii) 0.1 to 10 parts by weight of fluorine-based silane, (iii) 0.001 to 0.5 parts by weight of catalyst, The sol-gel reaction is carried out at 15 to 90 ° C. for 0.5 to 40 hours at 15 to 90 ° C. with a mixture comprising (iv) 0.01 to 10 parts by weight of water and (v) 20 to 99.5 parts by weight of organic solvent. In this case, it is advantageous to dry and cure the film after the sol-gel reaction to adjust the molecular weight of the final reactant to about 2,000 to 20,000. (B) 0.02 to 50 parts by weight of the conductive polymer is added to the prepared sol-gel reactant to prepare a coating composition.

The solids content of the coating composition as a whole is preferably 0.5 to 30% by weight, and the organic solvent may be selectively added in consideration of drying and curing temperatures.

The present invention provides a coating film prepared using the coating composition.

That is, the coating composition of the present invention can be used as a display antireflective coating material, and can be applied after the hard coating layer is applied on the substrate or the substrate, or can be applied on the substrate / hard coating / high refractive layer. In this case, the substrates commonly used include glass, plastic substrates, films, and the like, and the coating method may be freely selected according to the substrate. As the hard coat layer, an ultraviolet curable resin may be used, and inorganic nanoparticles may be dispersed and used in an ultraviolet curable resin in order to improve wear resistance.

The coating composition may be coated on a substrate according to a conventional method, the drying and curing temperature after coating is preferably 70 to 120 ℃, the drying and curing time is 10 to 40 hours.

In general, the lower the refractive index of the antireflective layer is preferable, and the greater the difference in refractive index with the lower layer, the greater the antireflective effect. On the other hand, the thickness of the antireflection layer is determined by the refractive index of the material used and the wavelength of the incident light. For example, when the hard coating layer and the radiation prevention layer are applied on the substrate, the refractive index of the hard coating layer is 1.51, the refractive index of the antireflection layer is 1.38, the incident light If the design wavelength of is 550 nm, the desired thickness of the antireflection layer is 100 nm by optical design. The preferred thickness of the coating film according to the invention is 50 to 200 nm.

Hereinafter, preferred examples and comparative examples are presented to aid in understanding the present invention. However, the following examples are merely provided to more easily understand the present invention, and the present invention is not limited to the following examples.

<Example 1>

A mixture of 10 g of tetraethoxysilane, 3 g of heptadecafluorodecyltrimethoxysilane, 3 g of water, 0.12 g of hydrochloric acid, and 58.88 g of ethanol was subjected to a sol-gel reaction. The reaction temperature was 78 ℃, pH was 2, the reaction time was 3 hours. After the reaction was completed, the reaction mixture was cooled to room temperature and 25 g of a conductive polymer Baytron PET V2 was added thereto.

The antireflective coating composition prepared by the above method was applied on a hard coating film with a dry thickness of 100 nm by a roll coating method. The coated film was cured for 10 hours in a 120 ℃ oven.

<Example 2>

A film coated with an antireflective coating composition was prepared in the same manner as in Example 1 except that 25 g of Baytron PH was added instead of Baytron PET V2 as the conductive polymer.

<Example 3>

Except for using heptadecafluorodecyltriisopropoxysilane as the fluorine-based silane was prepared in the same manner as in Example 1 coated with a coating composition for antireflection.

<Example 4>

Except for using 83.86 g of ethanol and 0.02 g of Baytron PET V2, a film coated with an antireflective coating composition was prepared in the same manner as in Example 1.

Example 5

A film coated with an antireflective coating composition was prepared in the same manner as in Example 1 except that 60.88 g of ethanol and 1 g of heptadecafluorodecyltrimethoxysilane were used.

<Example 6>

A film coated with an antireflective coating composition was prepared in the same manner as in Example 1 except that 51.88 g of ethanol and 10 g of heptadecafluorodecyltrimethoxysilane were used.

<Example 7>

An antireflective coating composition was prepared in the same manner as in Example 1 except that a mixed organic solvent including 35.28 g of ethanol, 11.8 g of diacetone alcohol, and 11.8 g of butyl cellosolve was used.

<Example 8>

Except for using a mixed organic solvent containing 78.1 g of ethanol, 0.39 g of diacetone alcohol, and 0.39 g of butyl cellosolve, a film coated with an antireflective coating composition was prepared in the same manner as in Example 1.

Comparative Example 1

Except for using the conductive polymer Baytron PET V2 in Example 1 was prepared in the same manner as in Example 1.

Comparative Example 2

Except for using heptadecafluorodecyltrimethoxysilane in Example 1 was prepared in the same manner as in Example 1 except that methyltriethoxysilane.

Comparative Example 3

Except for using 68.88 g of ethanol, 15 g of Baytron PET V2 was prepared in the same manner as in Example 1 coated with a coating composition for antireflection.

Experimental Example 1

The contact angle, pen erase, dust removal and reflectance of the coating films prepared in Examples and Comparative Examples were measured to evaluate the ease of decontamination and optical properties.

1) contact angle

The contact angle to the water of the coating film was measured to determine the ease of removal to the liquid contaminant. At this time, the contact angle is more than 90 ° decontamination is implemented.

2) pen erase

After writing with the oil pen, rubbing with a cotton cloth, and visually observed the eraser was judged as upper and lower.

3) dust removal

The coating film having a size of 10 cm in length and length was rubbed with a cotton cloth 20 times, and then spray powder was sprayed 5 times at 1 minute intervals at a distance of 30 cm. The coated surface where the powder settled down was blown with air of 2 atmospheres for 10 seconds, and the remaining powder was visually observed, and the powders were expressed in the order of the lower and lower order.

4) reflectance

After the back side of the coating film was blacked, reflectance was measured with N & K's spectrophotometer to evaluate the antireflection property with a minimum reflectance value.

Contact angle Pen erase Dust removal Minimum reflectance (%) Haze (%) Example 1 102 Prize Prize 2.0 0.7 Example 2 104 Prize Prize 1.8 0.6 Example 3 97 Prize Prize 2.2 0.6 Example 4 100 Prize Ha 1.6 0.6 Example 5 80 medium Prize 2.8 0.7 Example 6 104 Prize Ha 1.2 0.8 Example 7 104 Prize Prize 1.8 0.4 Example 8 103 Prize Prize 2.0 0.6 Comparative Example 1 104 Prize Ha 1.5 0.3 Comparative Example 2 70 Ha Prize 3.3 0.7 Comparative Example 3 99 Prize Prize 2.1 1.0

In Table 1, 'top', 'middle', and 'bottom' of the pengium exhibit removal performance of '90% or more ', '70 to 90%', and '70% or less', respectively.

From Table 1, it can be seen that the coating film made of the coating composition containing the conductive polymer is excellent in dust removal function, when it does not contain a fluorine-based silane has a high surface energy, high reflectance and liquid contamination removal It turned out that easiness falls.

 The display antireflective coating composition of the present invention includes a fluorine-based silane having a low surface tension, a conductive polymer having an antistatic property, and a solvent. In addition, the coating film prepared from the coating composition of the present invention is excellent in the anti-reflective properties and the anti-reflective properties and liquid removal of dust, such as fingerprints, by controlling the refractive index, surface energy, and conductivity, CRT or flat panel display film It can be usefully applied to the outermost front of the display regardless of the type of substrate, hard coating or anti-static coating or other coating layer such as anti-glare coating.

Claims (9)

(a) 0.3 to 15 parts by weight of (i) alkoxysilane, (ii) 0.1 to 10 parts by weight of fluorine silane, (iii) 0.001 to 0.5 parts by weight of catalyst, (iv) 0.01 to 10 parts by weight of water, and (v) alcohol A sol-gel reactant prepared from 20 to 99.5 parts by weight of a mixed organic solvent including a solvent such as a ketone solvent and at least one solvent selected from the group consisting of cellosolve solvents; And (b) 0.02 to 50 parts by weight of the conductive polymer Display antireflective coating composition comprising a. delete delete The fluorine-based silane is at least one member selected from the group consisting of tridecafluorooctyltriethoxysilane, heptadecafluorodecyltrimethoxysilane, and heptadecafluorodecyltriisopropoxysilane. Coating composition. The coating composition according to claim 1, wherein the conductive polymer is polythiophene. The coating composition of claim 5, wherein the conductive polymer is doped with at least one compound selected from the group consisting of glutamic acid, alkyl sulfonic acid, polystyrene sulfonic acid anion, and copolymers of styrene sulfonic acid and styrene sulfonic acid anion. The coating composition of claim 1, wherein the catalyst is at least one selected from the group consisting of acids, metal salts, and mixtures thereof. Display antistatic coating film prepared from the coating composition of claim 1. The coating composition according to claim 1, wherein the content of at least one solvent selected from the group consisting of ketone solvents and cellosolve solvents is 30% by weight or less based on the total weight of the mixed solvent.